It is well established that electronic conical intersections (CIs) in molecular systems can be induced by laser light, even in diatomic molecules. The emergence of these light-induced degeneracies leads to strong coupling among electronic, vibrational, and photonic modes, which significantly influences ultrafast nuclear dynamics. In this work, we perform pump-probe numerical simulations on the NaH molecule, considering the first three singlet electronic states $[X^1{\mathrm{\Sigma }}^{+}\left(X\right),A^1{\mathrm{\Sigma }}^{+}\left(A\right), \text{and} B^1\mathrm{\Pi }\left(B\right)]$ and including several light-induced degeneracies in the theoretical model. To elucidate the ultrafast molecular dynamics, we study the combined effects of multiple light-induced nonadiabatic couplings and rotational motion of the nuclei together with the situation when the electronic angular momentum projected onto the diatomic axis couples with the angular momentum of the nuclei. We then calculate key dynamical observables such as dissociation probabilities, kinetic energy release (KER) spectra, and angular distributions of the photofragments within and above the linear regime. The discrepancies between the different employed models are relatively minor for the dissociation probabilities and KER spectra. In contrast, for angular distributions, the inclusion of electronic spin and orbital angular momentum leads to substantial differences between the three applied schemes in the small ejection angle region.

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• Atomic & molecular processes in external fields